It is now widely recognized and accepted that release into the atmosphere of chlorofluorocarbon(CFC)-based refrigerants, such as refrigerant R12, has a deleterious effect upon the ozone layer that surrounds the earth. Production of CFC-based refrigerants has been severely curtailed, and the cost of refrigerant for service purposes is increasing. It is therefore standard practice in the refrigeration system service industry to recover, purify and (recycle or reclaim) re-use refrigerant, rather than merely to vent such refrigerant into the atmosphere and replace with new refrigerant as had been common practice in the past. U.S. Pat. Nos. 4,768,347, 4,805,416, 4,939,905, 5,005,369, 5,095,713 and 5,127,239, all assigned to the assignee hereof, disclose equipment for recovering, purifying and/or recharging refrigerant in a refrigeration system service environment.
As currently envisioned, R12 refrigerant will eventually be replaced by different types of refrigerant in production of new refrigeration systems. For example, R12 refrigerant is being replaced by R134a refrigerant in the automotive industry--i.e., in automotive air conditioning systems. However, because these refrigerants and their associated lubricants are chemically incompatible with each other, inadvertent mixture of even small amounts of the different refrigerants can cause severe damage to and early failure of the refrigeration system. SAE specifications require different service fittings on automotive air conditioning systems using different types of refrigerants--i.e., 1/4-inch flare fittings on R12 equipment and 1/2-inch acme fittings on R134a equipment. However, the use of adapters in the service industry may still result in inadvertent mixing of refrigerant/lubricant types, with consequent damage to the system under service or to the service equipment itself.
There is therefore a need in the refrigerant service industry, particularly the automotive air conditioning system service industry, for refrigerant recovery equipment that is particularly designed and adapted to reduce likelihood of inadvertent mixing of incompatible refrigerant types. It is a general object of the present invention to provide such equipment.